How It Works
This calculator works in 4 steps.
Enter the total dilution
Type DF or the stock and target concentrations.
Enter the final volume
Type the volume of the final solution.
Enter the minimum transfer
Type the smallest volume the pipette or SOP allows.
Read the plan
The calculator reports direct OK, or a round predilution and the final transfer volume.
The Formula
The formula compares the direct transfer with the minimum and splits the factor when needed.
V_direct = V_final / DFDF_max = V_final / V_minDF₁ ≥ DF / DF_max (rounded up to a round value)- DF:
- Total dilution factor
- V_min:
- Minimum allowed transfer
- V_final:
- Final volume
- DF₁:
- Predilution factor
A 1:10,000 dilution into 1,000 µL with a 1 µL minimum needs 0.1 µL direct. A 1:10 predilution followed by a 1:1,000 step uses a 1 µL final transfer.
Conversion Table
The conversion table checks 6 dilutions against a minimum transfer and gives a workable plan.
| Total DF | Minimum transfer | Final volume | Direct transfer | Plan | Final-step transfer |
|---|---|---|---|---|---|
| 10,000 | 1 µL | 1,000 µL | 0.1 µL | 1:10 then 1:1,000 | 1 µL |
| 1,000 | 2 µL | 1,000 µL | 1 µL | 1:10 then 1:100 | 10 µL |
| 50,000 | 1 µL | 200 µL | 0.004 µL | 1:500 then 1:100 | 2 µL |
| 100,000 | 2 µL | 1,000 µL | 0.01 µL | 1:200 then 1:500 | 2 µL |
| 500 | 5 µL | 1,000 µL | 2 µL | 1:10 then 1:50 | 20 µL |
| 2,000 | 0.5 µL | 500 µL | 0.25 µL | 1:10 then 1:200 | 2.5 µL |
What Is the Minimum Transfer Volume Calculator?
The Minimum Transfer Volume Calculator is a tool that checks whether a dilution needs a transfer below a set minimum volume and, if so, returns the smallest intermediate dilution that brings every transfer above the minimum. The minimum comes from the user's pipette or SOP, such as 1 µL or 2 µL.
The calculator finds the largest single-step factor the minimum allows (final volume ÷ minimum volume). When the total factor exceeds that limit, the calculator splits the dilution into a predilution and a final step, picking a round predilution factor such as 1:10, 1:50, or 1:100.
Common Uses
There are 5 main uses of this calculator.
High-factor dilutions
Users avoid sub-microliter transfers for 1:10⁴ and beyond.
SOP compliance
Labs enforce a minimum transfer stated in the SOP.
Automation limits
Automation teams respect liquid handler minimums.
Viscous stocks
Users raise the minimum for glycerol and DMSO stocks.
Audit preparation
QA teams document why a predilution step exists.